Hindu-Arabic numerals were developed around 400 B.C. and are used in a decimal (base 10) system. Which of these is true about Arabic numerals?
A.
They were invented in Arabia and brought to Europe during a war.
B.
They were invented in Nepal and then spread by Hindu monks.
C.
They were invented by Europeans who studied ancient Arab texts.
D.
They were invented in India and brought to Europe by Arabs.